+class Throwable e where
+ toThrowable :: e -> Throwable
+
+messageOfException :: Throwable e => e -> String
+messageOfException = getMessageThrowable . toThrowable
+
+causeOfException :: Throwable e => e -> Maybe Throwable
+causeOfException = getCauseThrowable . toThrowable
+
+instance Throwable Throwable where
+ toThrowable = id
+instance Throwable Exception where
+ toThrowable = Java.unsafeCoerce
+